Fair Value Measurements (Non-Recurring) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Mar. 31, 2012 Financing receivables and loans held for sale [Member]	Mar. 31, 2011 Financing receivables and loans held for sale [Member]	Mar. 31, 2012 Cost and equity method investments [Member]	Mar. 31, 2011 Cost and equity method investments [Member]	Mar. 31, 2012 Long Lived Assets, Including Real Estate [Member]	Mar. 31, 2011 Long Lived Assets, Including Real Estate [Member]	Mar. 31, 2012 Total [Member]	Mar. 31, 2011 Total [Member]	Mar. 31, 2012 Fair Value, Inputs, Level 2 [Member] Financing receivables and loans held for sale [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Financing receivables and loans held for sale [Member]	Mar. 31, 2012 Fair Value, Inputs, Level 2 [Member] Cost and equity method investments [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Cost and equity method investments [Member]	Mar. 31, 2012 Fair Value, Inputs, Level 2 [Member] Long Lived Assets, Including Real Estate [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Long Lived Assets, Including Real Estate [Member]	Mar. 31, 2012 Fair Value, Inputs, Level 2 [Member] Total [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 2 [Member] Total [Member]	Mar. 31, 2012 Fair Value, Inputs, Level 3 [Member] Financing receivables and loans held for sale [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Financing receivables and loans held for sale [Member]	Mar. 31, 2012 Fair Value, Inputs, Level 3 [Member] Cost and equity method investments [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Cost and equity method investments [Member]	Mar. 31, 2012 Fair Value, Inputs, Level 3 [Member] Long Lived Assets, Including Real Estate [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Long Lived Assets, Including Real Estate [Member]	Mar. 31, 2012 Fair Value, Inputs, Level 3 [Member] Total [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member] Total [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value assets measured on non recurring basis	$ 1,439										$ 196	$ 158	$ 0	$ 0	$ 127	$ 1,343	$ 323	$ 1,501	$ 2,015	$ 5,159	$ 73	$ 403	$ 1,271	$ 3,282	$ 3,359	$ 8,844
Adjustments To Assets Measured At Fair Value On Non Recurring Basis	$ (3)	$ (5)	$ (126)	$ (363)	$ (21)	$ (50)	$ (152)	$ (568)	$ (299)	$ (981)